People are generally aware of the most common causes of hallucinations, like schizophrenia and a really high fever. But lesser known are the more rare causes; here are six you probably haven't heard about.

The mystery of a missing 14-year-old autistic boy, Avonte Oquendo, whose face troubled New York subway riders since early October, came to a close when his remains were pulled from the East River earlier this month. Now, to protect families across the nation, Democratic U.S. Sen. Charles Schumer has proposed a bill to provide GPS tracking devices for children with autism: “Avonte’s Law.” Schumer, the senior senator of New York, intends to introduce the legislation today, The Wall Street Journalreported.

"Avonte's running away was not an isolated incident," he stated at a news conference in his Midtown office. Last seen leaving his school in Long Island City, Oquendo was known to be non-verbal, an impairment which affects up to 25 percent of individuals with one of the autism spectrum disorders. Schumer recommends expanding the Missing Alzheimer's Disease Patient Assistance Program, which provides GPS tracking devices to families of people with Alzheimer’s disease. These devices can be worn as wristbands, tied to shoelaces, attached to belts, or even sewn into clothing. The technology enables law enforcement agencies to easily locate adults who have wandered away from their homes.

"There is no reason the same program that's been successful with elderly people with Alzheimer's who wander cannot be used for kids like Avonte who have autism and wander," Schumer stated. He is hoping to establish a voluntary program, whereby the devices could be given to parents and schools, and though administered by local police departments, the program would be overseen by the Justice Department. The new legislation, then, would rely on federal funding. “We are proposing to set aside $10 million to get this program up and running,” a representative from Schumer’s office told Al Jazeera America.

The New York City police continue to investigate the circumstances of Oquendo's death. Initially, the New York City subway system had been the focus of their search because the autistic teen had been fascinated by the underground train system. Posters with the teen’s face had graced most stations throughout the city subway system yet any information provided by passengers did not lead to his whereabouts. Two weeks ago, some of his body parts washed up on a beach in northern Queens, near the Bronx-Whitestone Bridge. The location was several miles from his school. Lisa Goring, an executive at Autism Speaks, told NBC News that some children with autism are drawn to water and for this reason they must be prevented from wandering off as they are likely to drown. Her organization, an advocacy group founded in 2005, supports Schumer’s proposed legislation and would like to see additional funding for practical skills like swimming lessons.